Root Dynamics of a Shortgrass Ecosystem

Abstract

Seasonal dynamics of roots of a shortgrass ecosystem were determined at 2-week intervals for the two growing seasons of 1969 and 1970 and at monthly intervals during the intervening fall and winter. Soil cores were taken to a depth of 80 cm during the first growing season to determine the amount and distribution of roots in the soil profile. Root samples in the second year were only taken to a depth of 10 cm, with periodic sampling to 80 cm. Some 55% of the root weight was found in the 0- to 10-cm segment, and 69% was found in the upper 20 cm of the soil profile. There were significant differences among sampling dates in root weights in the upper 10-cm increment. The mass of roots in the lower portion of the profile remained somewhat constant throughout the sampling period. No significant differences were found in the root mass among four grazing intensity treatments (ungrazed, light, moderate, and heavy).